Transfusion strategy and allo-immunization to red blood cell antigens after allogeneic hematopoietic stem cell transplantation with partial donor/recipient Rh matching.

Background: After allogeneic hematopoietic stem cell transplantation (alloHSCT), the HAS recommends transfusing red blood cells (RBCs) matched for Rh ("Rhesus") phenotypes, and the EFS recommends respecting both donor and recipient Rh phenotypes. We previously reported a 10.3% allo-immunization rate in 58 Rh-incompatible alloHSCT recipients transfused in the donor phenotype: none was directed against the mismatched donor Rh antigens.

Blood group genotype matching for transfusion.

The last decade has seen significant growth in the application of DNA-based methods for extended antigen typing, and the use of gene sequencing to consider variation in blood group genes to guide clinical care. The challenge for the field now lies in educating professionals, expanding accessibility and standardizing the use of genotyping for routine patient care. Here we discuss applications of genotyping when transfusion is not straightforward including when compatibility cannot be demonstrated by routine methods, when Rh type is unclear, when allo- and auto-antibodies are encountered in stem cell and organ transplantation, for prenatal testing to determine maternal and foetal risk for complications, and Group A subtyping for kidney and platelet donors.

Molecular dynamics of the human RhD and RhAG blood group proteins.

Blood group antigens of the RH system (formerly known as "Rhesus") play an important role in transfusion medicine because of the severe haemolytic consequences of antibodies to these antigens. No crystal structure is available for RhD proteins with its partner RhAG, and the precise stoichiometry of the trimer complex remains unknown. To analyse their structural properties, the trimers formed by RhD and/or RhAG subunits were generated by protein modelling and molecular dynamics simulations were performed.

Eleven years of alloimmunization in 6496 patients with sickle cell disease in France who received transfusion.

Red blood cell (RBC) transfusion is a major therapy for sickle cell disease (SCD). Patients are at risk of forming antibodies to RBC antigens, which can result in the impossibility to find compatible units and can cause hemolytic transfusion reactions. This retrospective study investigates the evolution of RBC consumption and the frequencies, specificities, and chronology of the appearance of antibodies in a population of patients consistently receiving RH (C, D, E, c, e) and K-matched RBC units (RBCus) from a predominantly European donor population.

Alloimmunisation against red blood cells in sickle cell disease: transfusion challenges in high-income and low-income countries.

Sickle cell disease is the most frequent inherited disorder in sub-Saharan Africa and in many high-income countries (HICs). Transfusion is a key element of treatment, but it results in high rates of alloimmunisation against red blood cell antigens and post-transfusion haemolysis, which can be life-threatening in severe cases. The prevention of alloimmunisation is, therefore, an important issue in both HICs and in low-income countries (LICs).

A novel high-prevalence antigen in the Lutheran system, LUGA (LU24), and an updated, full-length 3D BCAM model.

Background: The basal cell adhesion molecule (BCAM) carries the antigens of the Lutheran (LU, ISBT005) system. We report a novel Lutheran antigen and propose an updated, full-length 3D model of BCAM.

Study Design And Methods: Red blood cell testing, antibody identification, and BCAM genomic DNA sequencing were done by standard methods.

Red blood cell alloimmunisation in sickle cell disease patients in the Democratic Republic of the Congo.

Objectives: To determine the prevalence of red blood cell (RBC) alloimmunisation and alloantibody specificity in sickle cell disease (SCD) patients in Kisangani, Democratic Republic of Congo (DRC) in comparison with those followed at the Centre Hospitalier Régional (CHR) de la Citadelle of Liège (Belgium).

Background: Data regarding RBC alloimmunisation (immune response of the organism to foreign erythrocyte antigens, antigens that lack on its own RBC) in SCD patients are scarce in sub-Saharan Africa.

Methods: We conducted a multi-site-based cross-sectional study among 125 SCD patients at Kisangani and 136 at the CHR de la Citadelle of Liège.

Two new Scianna variants causing loss of high prevalence antigens: ERMAP model and 3D analysis of the antigens.

Background: Scianna (Sc) antigens, seven high and two of low prevalence, are expressed on erythrocyte membrane-associated protein (ERMAP). We investigated SC (ERMAP) in individuals who made antibodies to high prevalence Scianna antigens, and propose a 3D model for ERMAP to precisely localize the residues associated with the known antigens.

Methods: Serological testing and DNA sequencing was performed by standard methods.

3D analysis of CROMER (DAF) and a new antigen CRAG.

Background: Cromer antigens are carried on decay accelerating factor (DAF, CD55), for which the crystal structure is available. We investigated two samples with an unidentified antibody to a high prevalence antigen and evaluate the location and characteristics of amino acids associated with antigens on the CD55 by 3D modelling.

Materials And Methods: Antigen typing and antibody identification were by standard methods.

How to avoid the problem of erythrocyte alloimmunization in sickle cell disease.

Erythrocyte alloimmunization is a major barrier to transfusion in sickle cell disease (SCD) because it can lead to transfusion deadlock and the development of life-threatening hemolytic transfusion reactions (HTRs). Several risk factors have been identified, such as blood group polymorphism in these patients of African ancestry frequently exposed to antigens they do not carry and an inflammatory clinical state of the disease. The most important preventive measure is prophylactic red blood cell antigen matching, and there is a consensus that matching for Rh (D, C, E, c, e) and K antigens should be performed for all SCD patients.